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BACKGROUND: Social distancing was implemented worldwide due to the coronavirus (COVID-19) pandemic. This impacted physical activity levels and increased the time spent in sedentary behaviors which may contributed to the emergence of increased musculoskeletal complaints. OBJECTIVE: To assess the consequences of social distancing for the increase in perceived pain of students and professors from higher education institutions. METHODS: One thousand two hundred and fifty-four participants responded to an online survey containing sociodemographic information and questions related to daily habits, physical activity profile, and musculoskeletal pain before and during the pandemic. Levels of concentration, nervousness, productivity, and visual fatigue were also assessed. The primary outcome was presence of perceived pain before and during the pandemic, dichotomized between those with and without increased pain during the pandemic. RESULTS: Perceived pain increased during the pandemic (p 6 hours (p = 0.041; PR = 1.44; 95% CI = 1.02–2.06). Nervousness (p = 0.001) and visual fatigue (p = 0.001) increased, whereas concentration (p = 0.001) and productivity (p = 0.001) reduced during the pandemic. CONCLUSIONS: Reduced physical activity practice and increased time in sedentary behavior and electronic device usage during the pandemic were associated with increased musculoskeletal pain in students and professors from higher education institutions. Decreased concentration and productivity and increased nervousness and visual fatigue were also observed during the pandemic.

Purpose To investigate if blue-blocking lenses are effective in reducing the ocular signs and symptoms of eye strain associated with computer use. Design Double-masked, randomized controlled trial. Methods A total of 120 symptomatic computer users were randomly assigned (1:1) into a “positive” or “negative” advocacy arm (ie, a clinician either advocating or not advocating for the intervention via a prerecorded video). Participants were further sub-randomized (1:1) to receive either clear (placebo) or blue-blocking spectacles. All participants were led to believe they had received an active intervention. Participants performed a 2-hour computer task while wearing their assigned spectacle intervention. The prespecified primary outcome measures were the mean change (post- minus pre-computer task) in eye strain symptom score and critical flicker-fusion frequency (CFF, an objective measure of eye strain). The study also investigated whether clinician advocacy of the intervention (in a positive or negative light) modulated clinical outcomes. Results All participants completed the study. In the primary analysis, for CFF, no significant effect was found for advocacy type (positive or negative, p = .164) and spectacle intervention type (blue-blocking or clear lens, p = .304). Likewise, for eye strain symptom score, no differences were found for advocacy (p = .410) or spectacle lens types (p = .394). No adverse events were documented. Conclusions Blue-blocking lenses did not alter signs or symptoms of eye strain with computer use relative to standard clear lenses. Clinician advocacy type had no bearing on clinical outcomes.

Purpose: The aim of this study was to determine prevalence, symptoms frequency and associated risk factors of digital eye strain (DES) among children attending online classes during COVID-19 pandemic. Methods: The online electronic survey form was prepared on the Google app. Children/parents were asked to indicate the total duration of digital device use before and during COVID era. The symptoms of DES, its severity and frequency were recorded & measured with the Computer Vision Syndrome Questionnaire. Results: Two hundred and sixty one parents responded to the questionnaire, of these 217 were complete. Mean age of children was 13 ± 2.45 years. Mean duration of digital device used during COVID era was 3.9 ± 1.9 h which is more than pre COVID era (1.9 ± 1.1 h, P = 5 h in COVID era as compared to 1.8% (n = 4) before COVID era. The most common digital device used were smartphones (n = 134, 61.7%). One hundred and eight children (49.8%) were attending online classes for >2 h per day. Prevalence of DES in our cohort is 50.23% (109/217). Of these 26.3% were mild, 12.9% moderate and 11.1% of severe grade. Most common symptoms were itching and headache (n = 117, 53.9%). Multivariate analysis revealed age >14 years (P = 0.04), male gender (P = 0.0004), smartphone use (P = 0.003), use of device >5 h (P = 0.0007) and mobile games >1 h/day (P = 0.0001) as independent risk factors for DES in children. Conclusion: There is an increased prevalence of DES among children in COVID era. Parents should be considerate about duration, type and distance of digital device use to avoid DES symptoms in children.

Purpose To investigate the effects of watching ultra-high-definition television (UHD TV) on subjective ocular fatigue and objective ocular surface indices. Methods A total of 76 volunteers were recruited for this study. Subjects watched UHD TV for 10 minutes at a viewing distance of 110 cm. Best-corrected visual acuity, refractive errors, tear break-up time, corneal staining grading, conjunctival redness grading by slit-lamp examination, tear meniscus measurement by anterior segment optical coherence tomography, and ocular symptom scores were obtained before and immediately after watching UHD TV. Subgroup analyses were conducted according to participant age (old age group >50 years vs. young age group ≤50 years) and dry-eye syndrome (presence vs. absence). The relationship between subjective and objective indices was evaluated. Results The mean age of subjects was 39.6 ± 12.4 years. Watching UHD TV induced a decrease in tear break-up time in the non-dry-eye group (p < 0.001) but not in the dry-eye group (p = 0.726). Corneal staining grades increased in all subgroups, and the changes were particularly larger in the older group (p = 0.038). The increase in ocular symptom scores was larger in the dry-eye group (p = 0.08) and in the older group (p = 0.016). The decrease in tear break-up time and ocular symptom scores after watching UHD TV was significantly correlated with tear break-up time. Conclusions Tear break-up time significantly decreased in non-dry-eye subjects after watching UHD TV. Subjective ocular discomfort increased significantly in subjects over the age of 50 and in participants with dry-eye syndrome.

Background Many ophthalmic lens manufacturers are currently marketing blue-blocking filters, which they claim will reduce symptoms of Digital Eye Strain (DES). However, there is limited evidence to support the proposal that DES results from the blue light emitted by electronic screens. Objective This investigation compared the effect of blue-blocking filters on DES symptoms with a no-filter lens, using a double-blind methodology. Methods Twenty-four subjects were required to perform a 20-minute reading task from a tablet computer. They wore either lenses containing a blue-blocking filter (TheraBlue 1.67 or TheraBlue polycarbonate) or a CR-39 control lens which did not include a filter. Immediately following each session, subjects completed a questionnaire to quantify symptoms of DES. Results While a significant increase in symptoms was observed immediately following the near vision task (p = 0.00001), no significant difference in symptoms was found between the 3 lens conditions (p = 0.74). Conclusions There is little evidence at this time to support the use of blue-blocking filters as a clinical treatment for DES. Management of other ocular factors, as well as the creation of an optimal environment for screen viewing, are more likely to provide greater success in minimizing symptoms.

During the COVID-19 pandemic, computer vision syndrome (CVS) related to online classrooms were unavoidable. This cross-sectional study aimed to explore the prevalence, characteristics and associated factors of CVS. A total of 527 students who were currently studying in a virtual classroom (70.40% female, mean (standard deviation; SD) age of 20.04 (2.17) years) were included. The prevalence of CVS assessed by an online CVS-Questionnaire was 81.0% (427/527). Comparing with those in the period before the online study, an increase in screen time (interquartile range) in students with and without CVS was 3 (0–3) and 2 (1–5) h, respectively. Overall, 516 students (97.9%) experienced at least one symptom. The most frequent symptom in CVS subjects was eye pain (96.5%). The most intense symptoms were the feeling of worsening eyesight (15.9%). The factors associated with CVS were female (p < 0.001), age (p = 0.010), atopic diseases (p = 0.020), prior ocular symptoms (p < 0.001), astigmatism (p = 0.033), distance from display

Stereoscopic viewing has an impact on ocular dynamics, but its effects on accommodative functions are not fully understood, especially for autostereoscopic viewing. This study aimed to investigate the changes in dynamic accommodative response, accommodative amplitude, and accommodative facility of myopes after autostereoscopic visual training.We enrolled 46 adults (men = 22 and women = 24; age = 21.5 ± 2.5 [range = 18-25] years, spherical equivalent: -4.52 ± 1.89 [-8.88 to -1.75] diopters [D]) who visited the EyeENT Hospital of Fudan University. The study population was randomly divided into three-dimensional (3D) and two-dimensional (2D) viewing groups to watch an 11-minute training video displayed in 3D or 2D mode. Dynamic accommodative response, accommodative facility, and accommodative amplitude were measured before, during, and immediately after the training. Accommodative lag and the variability of accommodation were also analyzed. Visual fatigue was evaluated subjectively using a questionnaire.Accommodative lag decreased from 0.54 ± 0.29 D to 0.42 ± 0.32 D (P = 0.004), whereas accommodative facility increased from 10.83 ± 4.55 cycles per minute (cpm) to 13.15 ± 5.25 cpm (P0.001) in the 3D group. In the 2D group, there was no significant change in the accommodative lag (P = 0.163) or facility (P = 0.975), but a decrease in accommodative amplitude was observed (from 13.88 ± 3.17 D to 12.71 ± 2.23 D, P = 0.013). In the 3D group, the accommodative response changed with the simulated target distance. Visual fatigue was relatively mild in both groups.The immediate impact of autostereoscopic training included a decrease in the accommodative lag and an increase in the accommodative facility. However, the long-term effects of autostereoscopic training require further exploration.

Purpose. The contributory factors and symptoms for presbyopia progression have not been fully determined. The purpose of the study was to compare presbyopia progression in subjects with short and normal tear breakup time and to explore the severity of common ocular symptoms associated with presbyopia progression. Method. We conducted a clinic-based, retrospective, cross-sectional study. Inclusion criteria were bilateral phakic patients aged 40–69 years with best-corrected distance visual acuity better than 20/30, and exclusion criteria were the use of glaucoma eye drops, any disease affecting vision, or history of ocular surgery. We measured the binocular near add power and compared the results using Kaplan-Meier analysis. Association between near add power and ocular symptoms was explored. Results. There were 1411 participants (mean age of 50.1 years). There were no significant differences in age, intraocular pressure, spherical equivalent, astigmatism, or anisometropia between the sexes. Kaplan-Meier analysis indicated that women with short tear breakup time reached the endpoint (near add power of +3.00 D) significantly earlier than those with normal tear breakup time ( P = 0.043 ; Cox-Mantel test). Eye fatigue was most severe in the group with an add power of 1.25-2.00 D. Near add power was correlated with hyperopia, astigmatic errors, and anisometropia. Conclusions. This study suggests an exacerbation of presbyopia progression in women with short tear breakup time. Eye fatigue was most severe in those with an add power of 1.25-2.00 D.

The aims of the study were to investigate the ability and effectiveness of an oral intake of a fixed combination of zinc, L-carnitine, elderberry extract, black currant and Eleutherococcus extract in controlling the symptoms of eyestrain in videoterminal (VDT) users and to record its effects on contrast sensitivity. A single-center, phase II, observational, case-control, 1-month study in VDT workers without dry eye disease was carried out. Demographics and number of actual hours at VDT/day were taken into account. All subjects underwent a complete ophthalmic examination, including assessment of contrast sensitivity, and completed the computer vision symptom scale questionnaire at baseline and one month later. A total of 30 Caucasian subjects adhered to the required inclusion criteria and completed the study; 15 subjects were treated (T) and 15 were controls (C). All clinical data at baseline were similar in both groups (p > 0.05): after one month, all subjects had stable visual acuity, refractive defect and intraocular pressure (IOP); screen exposure time was unchanged. Regarding symptoms, at randomization, the groups had a similar score: 33.1 ± 3.3 in T and 32.8 ± 5.6 in C. One month later, the computer vision symptom scale (CVSS) questionnaire score decreased by −14.1 ± 3, 1 (p = 0.000) and −2.3 ± 1.8 (p = 0.568), respectively. Regarding contrast sensitivity, in group C the values of spatial frequencies remained unchanged, while they improved in almost all the cycles per degree stimuli in the treated group. Oral intake of a fixed combination of zinc, L-carnitine, elderberry extract, black currant and eleutherococcus extract can significantly improve contrast sensitivity and symptoms in VDT workers with no signs of dry eye disease.

Objectives: During the coronavirus disease 2019 (COVID-19) self-quarantine period, the transition to online-course has profoundly changed the learning modes of millions of school-aged children and put them at an increased risk of asthenopia. Therefore, we aimed to determine associations of the total screen/online-course time with asthenopia prevalence among that children during the COVID-19 pandemic, and whether the associations were mediated by psychological stress.Methods: Asthenopia was defined according to a validated computer vision syndrome questionnaire (CVS-Q). We used CVS-Q to collect the frequency and intensity of 16 asthenopia-related eye symptoms of 25,781 children. Demographic features, eye care habits, visual disorders, lifestyle, psychological and environmental factors, were also collected.Results: The overall asthenopia prevalence was 12.1%, varying from 5.4 to 18.2% across grade/gender-classified subgroups. A 100-h increment of total screen/online-course time were associated with an increased risk of asthenopia by 9% [odds ratio (OR) = 1.09] and 11% (OR = 1.11), respectively. Mediation analysis showed that the proportions of total effects mediated by psychological stress were 23.5 and 38.1%, respectively. Age, female gender, having myopia or astigmatism, bad habits when watching screens were also risk factors. Conversely, keeping 34–65 cm between eyes and screen, increased rest time between classes, and increased eye exercise were all associated with a decreased risk.Conclusion: Our study indicated that the influence of long total screen or online-course time on psychological stress increases asthenopia risk. The findings of this study have provided a new avenue for intervening screen-related asthenopia in addition to incorporating a reasonable schedule of online courses into educational policy.

Computer vision syndrome is common and affects performance of visual tasks. Background illumination, light source, light compensation, position of the display, contrast and glare are environmental factors associated with computer vision syndrome. The aim of this study is to investigate the effects of reflected glare and visual field lighting on computer vision syndrome.In a reflected glare experiment, participants performed a two-hour visual task using a glossy, matte, or glare-free surface display in two visual environments (normal, glare). In a visual field lighting experiment, participants performed the visual task in dim lighting, uneven supplementary lighting, or uniform supplementary lighting. Visual function parameters, including critical fusion frequency, heterophoria, amplitude of accommodation and accommodative facility were evaluated by the investigators and a visual fatigue questionnaire was completed before and after the visual task. Visual performance was also recorded. In addition, the variation of pupil size under different lighting conditions was analysed.Critical fusion frequency was the only visual function parameter which decreased significantly after the visual task. The questionnaire score was significantly higher in a glare environment and was lower when the task was performed using a glare-free display. Visual performance was significantly worse in the glossy display group. The increment in the questionnaire score was smaller in the uniform supplementary lighting group. Visual performance was significantly worse in the dim lighting or uneven supplementary lighting group, but not in the uniform supplementary lighting group. Variation in pupil size was significantly greater in the dim lighting condition than in the supplementary lighting condition.Critical fusion frequency is an effective indicator of computer vision syndrome. Glare-free displays could alleviate visual fatigue and preserve visual performance. Uniform supplementary lighting could decrease variation in pupil size and prevent eye strain.

SIGNIFICANCE The present study addresses the accommodative response and its dependence on the type of optical correction used. The results are discussed relative to their possible implications for myopia progression and visual fatigue. PURPOSE The accommodative response has been investigated owing to its possible relationship with the onset and progression of myopia and visual fatigue. This study explored the influence of wearing soft contact lenses in comparison with spectacles in terms of magnitude and variability of accommodation. In addition, we analyzed the intersession and intermethod repeatability. METHODS Dynamic accommodative response was recorded during 30-second epochs, at five different distances (50, 40, 33, 25, and 20 cm), in 21 individuals (mean refractive error ± SD, -0.79 ± 1.39 D) while wearing either soft contact lenses or spectacles on two different days. To assess repeatability, a second identical intervention was conducted. RESULTS Higher lags of accommodation were obtained with the use of soft contact lenses in comparison with the spectacle condition (P =.04, partial η 2 [η p 2] = 0.204), and similarly, a higher variability of accommodation at near distances was found during the soft contact lens measurement (P

Given the increasing use of electronic devices, and the increasing number of complaints with its use, we intend to evaluate the prevalence of manifestations of dry eye and ocular fatigue in a population of individuals, who use the computer daily to perform all their professional tasks, as well as to correlate these complaints with the number of hours of digital use as well as their possible improvement with behavioural measures and use of tear drops.A total of 77 individuals (154 eyes) were evaluated on two separate days with a 1-month interval. They completed two questionnaires: OSDI and PEG Eye Fatigue. An objective ocular surface assessment was performed: Schirmer test without anesthetic, DR-1a Dry Eye Monitor™, hyperemia evaluation, lacrimal break up, presence of keratitis and lesions in the conjunctiva, as well as near accommodation point and near convergence point. After the first evaluation, the subjects were divided into two groups: group A (2 hours of computer working) and group B (2 hours of computer working). Some environmental measures to reduce complaints and recommendation of use of artificial tears were explained to the latter.There was a statistically significant difference in the majority of the parameters evaluated in the group B, in relation to the morning period (group A) - tear film (p = 0.032), hyperemia (p0.001), BUT (p0.001), keratitis (p0.001), conjunctival lesion (p = 0.002) and accommodation point (p0.001). In the evaluation - one month later - there were no statistically significant differences in any of the parameters analysed in the group A, and in group B there was a decrease in most parameters at the end of that period - Schirmer test (p = 0.005), lacrimal film (p = 0.022), keratitis (p0.001), conjunctival lesion (p = 0.005) and fatigue score (p0.001).It was thus possible to show the appearance of ocular fatigue and ocular surface changes with prolonged use of computers (2 hours) as well as a significant improvement in symptomatology (subjective assessment) as well as of ocular surface changes (objective evaluation) with the implementation of postural measures, regular breaks and use of lubricants. This is the first study, to the best of our knowledge, of digital asthenopia in which, in addition to the subjective evaluation, the presence of ocular surface modifications (objective assessment) were evaluated and the respective improvement with the aforementioned ergophthalmological measures were evaluated.This survey highlights the increased overall level of awareness that we need to have to face the rapid and wide-scale changes driven by the emergence of digital technology and, more particularly, its impact on user's vision and posture. We concluded that the longer we use the electronic devices (more than two hours) the more severe the complaints and rates of ocular surface changes are. Environmental and ocular strategies can attenuate or even eliminate the discomfort caused by this syndrome, and increase professional performance and quality of life.Introdução: Atendendo ao uso crescente dos dispositivos eletrônicos, e o consequente aumento de queixas oftalmológicas com o seu uso, pretendemos com este estudo avaliar a prevalência de manifestações de olho seco e fadiga ocular numa população de indivíduos, de uma empresa de ‘outsourcing services’ e que utilizam o computador diariamente para realizar todas as suas tarefas. Material e Métodos: Um total de 77 indivíduos (154 olhos) foram avaliados em dois dias separados por um intervalo de um mês. Completaram dois questionários: OSDI e GPE Fadiga Ocular. Foi realizada uma avaliação objetiva da superfície ocular: teste de Schirmer sem anestesia, DR-1a Dry Eye Monitor™, avaliação hiperémia, rotura lacrimal, presença de queratite e lesões da conjuntiva, bem como avaliação do ponto próximo de acomodação e ponto próximo de convergência. Após a primeira avaliação, dividiu-se a amostra em dois grupos: grupo A (2 horas de trabalho no computador) e grupo B (2 horas de trabalho no computador). Ao grupo B foram explicadas algumas medidas ambientais para reduzir as queixas de astenopia digital e recomendou-se uso de lágrima artificial de acordo com as necessidades. Resultados: Observou-se uma diferença estatisticamente significante na maioria dos parâmetros avaliados no grupo B, quando comparado com o grupo no período da manhã (grupo A) - filme lacrimal (p = 0,032), hiperémia (p0,001), BUT (p0,001), queratite (p0,001), lesões da conjuntiva (p = 0,002) e ponto próximo de acomodação (p0,001). Na avaliaçã o - um mês depois - não houveram diferenças estatisticamente significativas em nenhum dos parâmetros analisados no grupo A, enquanto que no grupo B houve redução na maioria dos parâmetros ao final desse período - teste de Schirmer (p = 0,005), filme lacrimal (p = 0,022), queratite (p0,001), lesões da conjuntiva (p = 0,005), ponto de convergência próximo (p = 0,001) e score de fadiga (p0,001). Discussão: Foi assim possível objetivar o aparecimento de fadiga ocular e alterações da superfície ocular com o uso prolongado de computadores (2 horas) bem como uma melhoria significativa da sintomatologia (avaliação subjetiva) e melhoria da superfície ocular (avaliação objetiva) com a implementação de medidas posturais, pausas regulares e uso de lubrificantes. Este é o primeiro estudo, tanto quanto temos conhecimento, de astenopia digital em que para além da avaliação subjetiva se avalia a presença das referidas alterações da superfície ocular e a sua melhoria com as medidas ergoftalmológicas mencionadas. Conclusão: Este estudo realça a necessidade de estarmos alerta para as constantes e rápidas mudanças relacionadas com o uso crescente dos diferentes dispositivos digitais, bem como com o seu impacto oftalmológico e postural. Concluímos desta forma que quanto mais tempo usamos os dispositivos eletrónicos (2 horas), maiores são a probabilidade de desenvolver queixas e alterações da superfície ocular. As estratégias ambientais e oculares podem atenuar ou até mesmo eliminar o desconforto causado por esta síndrome e melhorar a qualidade de vida e o desempenho profissional.

Purpose To evaluate the use of digital devices, reading habits and the prevalence of eyestrain among urban Indian school children, aged 11–17 years. Methods The study included 576 adolescents attending urban schools who were surveyed regarding their electronic device usage. Additional information on the factors that may have an effect on ocular symptoms was collected. Results Twenty percent of students aged 11 in the study population use digital devices on a daily basis, in comparison with 50% of students aged 17. In addition to using these devices as homework aids, one third of study participants reported using digital devices for reading instead of conventional textbooks. The majority of students preferred sitting on a chair while reading (77%; 445 students), with only 21% (123 students) preferring to lie on the bed and 8 students alternating between chair and bed. There was a significant association between the students who preferred to lie down and those who experienced eyestrain, as reported by a little over one fourth of the student population (27%). Out of 576 students, 18% (103) experienced eyestrain at the end of the day after working on digital devices. Conclusions The increased use of digital devices by adolescents brings a new challenge of digital eyestrain at an early age. Our study reports the patterns of electronic device usage by school children, evaluates factors associated with eyestrain and highlights the need for further investigation of these issues.

Eye fatigue is a common health problem across all age groups. Herein, we explored the correlation between eye fatigue and thickness of the retinal nerve fiber layer (NFL). Included in the NFL are intrinsically photosensitive retinal ganglion cells (ipRGCs), which are associated with trigeminal pain. This retrospective cross-sectional study included outpatients with best-corrected visual acuity above 20/30 in both eyes and without dry eye, glaucoma, or retinal disease. A total of 1981 patients were initially enrolled and 377 patients were declared as eligible for the study analysis. We tested subjects for the presence of major ocular symptoms and measured thickness of ganglion cell complex (GCC) using optical coherence tomography. A total of 377 outpatients (46.4% men, mean age of 57.1 years) were enrolled for analysis, based on the interview-reported prevalence of six eye symptom, as follows: 31.5% for eye fatigue, 19.2% for blurring, 18.6% for dryness, 15.7% for photophobia, 13.5% for irritation, and 4.6% for pain. The macular GCC was significantly thicker in subjects with eye fatigue compared to the group not reporting eye fatigue (103.8 μm versus 100.3 μm, P = 0.014). Regression analysis identified eye fatigue (P = 0.026, β=0.122, adjusted for age and sex) and dryness (P =0.024, β=0.130) as significantly correlated with the macular GCC thickness, while the full macular thickness showed no significant correlation. In conclusions, eye fatigue and dryness were positively associated with thickness of the macular GCC. Nonvisual symptoms might therefore play a role in the development of eye fatigue.

Objective. The introduction of advanced endoscopic systems, such as the Storz Image1S and the Olympus Endoeye, heralds a new era of 3-dimensional (3D) visualization. The aim of this report is to provide a comprehensive overview of the neurophysiology of 3D view, its relevance in videoscopy, and to quantify the benefit of the new 3D technologies for both rigid and articulated instruments. Method. Sixteen medical students without any laparoscopic experience were trained each for a total of 27 hours. Proficiency scores were determined for rigid and articulated instruments under 2D and 3D visualization conditions. Results. A reduction in execution time of 14%, 28%, and 36% was seen for the rigid instruments, the da Vinci, and Steerable instruments, respectively. A reduction in errors of 84%, 92%, and 87% was seen for the rigid instruments, the da Vinci, and Steerable instruments, respectively. Conclusion. 3D visualization greatly augments endoscopic procedures. The advanced endoscopic systems employed in the recent study caused no visual fatigue or discomfort. The benefit of 3D was most distinct with articulated instruments.

Many manufacturers are currently marketing blue-blocking (BB) filters, which they claim will reduce the symptoms of digital eyestrain (DES). However, there is limited evidence to support the proposal that DES results from the blue light emitted by these devices.The visual and ocular symptoms commonly experienced when viewing digital screens are collectively termed DES. The emission spectrum of modern digital displays frequently includes a high percentage of blue light. Being higher in energy, these short wavelengths may contribute to DES. This study examined the effect of a BB filter on symptoms of DES during a sustained near-vision task.Twenty-three young, visually normal subjects were required to perform a 30-minute reading task from a tablet computer. The digital screen was overlaid with either a BB or neutral-density (ND) filter producing equal screen luminance. During each session, the accommodative response, pupil diameter, and vertical palpebral aperture dimension were measured at 0, 9, 19, and 29 minutes after the start of the reading task. Immediately following each session, subjects completed a questionnaire to quantify symptoms of DES.The BB filter blocked 99% of the wavelengths between 400 and 500 nm. The mean total symptom scores (±1 SEM) for the BB and ND filter conditions were 42.83 (3.58) and 42.61 (3.17), respectively (P = .62). No significant differences in accommodation or vertical palpebral aperture dimension were observed between the two filter conditions, although the magnitude of the mean accommodative response did increase significantly during the first 9 minutes of the task (P = .02).A filter that eliminated 99% of the emitted blue light was no more effective at reducing symptoms of DES than an equiluminant ND filter. There is little evidence at this time to support the use of BB filters to minimize near work-induced asthenopia.

OBJECTIVES To compare the effect of toric versus spherical soft contact lenses on objective measures of visual performance using visual acuity and electromyography of the orbicularis oculi muscle. METHODS Current soft contact lens wearers with -0.75 to -1.75 D astigmatism in each eye were binocularly fitted with toric (1-Day ACUVUE MOIST for astigmatism) and spherical (1-Day ACUVUE MOIST) contact lenses in random order. After each fitting and at 1-week follow-up, high- and low-contrast visual acuities were measured. Electromyography was used to objectively evaluate eyestrain. Linear mixed models were used to assess differences between toric and spherical contact lenses. RESULTS The mean age (±SD) of the 60 participants was 27.5±5.0 years, spherical refractive error was -3.68±2.01 D, and cylinder was -1.28±0.36 D. High- and low-contrast visual acuities with toric lenses were better than with spherical lenses at both fitting (toric high-contrast: -0.065±0.078 and low-contrast: 0.133±0.103 vs. spherical high-contrast: 0.001±0.104 and low-contrast: 0.224±0.107) and follow-up (toric high-contrast: -0.083±0.087 and low-contrast: 0.108±0.107 vs. spherical high-contrast: -0.015±0.095 and low-contrast: 0.211±0.104) (all P

Background The COVID-19 pandemic has led to worldwide school closures, with millions of children confined to online learning at home. As a result, children may be susceptible to anxiety and digital eye strain, highlighting a need for population interventions. Objective The objective of our study was to investigate whether a digital behavior change intervention aimed at promoting physical activity could reduce children’s anxiety and digital eye strain while undergoing prolonged homeschooling during the COVID-19 pandemic. Methods In this cluster randomized controlled trial, homeschooled grade 7 students at 12 middle schools in southern China were recruited through local schools and randomly assigned by the school to receive (1:1 allocation): (1) health education information promoting exercise and ocular relaxation, and access to a digital behavior change intervention, with live streaming and peer sharing of promoted activities (intervention), or (2) health education information only (control). The primary outcome was change in self-reported anxiety score. Secondary outcomes included change in self-reported eye strain and sleep quality. Results On March 16, 2020, 1009 children were evaluated, and 954 (94.5%) eligible children of consenting families were included in the intention-to-treat analysis. Children in the intervention (n=485, 6 schools) and control (n=469, 6 schools) groups were aged 13.5 (SD 0.5) years, and 52.3% (n=499) were male. The assigned interventions were completed by 896 children (intervention: n=467, 96.3%; control: n=429, 91.5%). The 2-week change in square-root–transformed self-reported anxiety scores was greater in the intervention (–0.23, 95% CI –0.27 to –0.20) vs control group (0.12, 95% CI 0.09-0.16; unadjusted difference –0.36, 95% CI –0.63 to –0.08; P=.02). There was a significant reduction in square-root–transformed eye strain in the intervention group (–0.08, 95% CI –0.10 to 0.06) compared to controls (0.07, 95% CI 0.05-0.09; difference –0.15, 95% CI –0.26 to –0.03; P=.02). Change in sleep quality was similar between the two groups. Conclusions This digital behavior change intervention reduced children’s anxiety and eye strain during COVID-19–associated online schooling. Trial Registration ClinicalTrials.gov NCT04309097; http://clinicaltrials.gov/ct2/show/NCT04309097

Objectives. This study aimed to describe the prevalence of ergonomic factors associated with computer vision syndrome (CVS), and knowledge and practices of computer usage among bank workers in the Cape Coast Metropolis, Ghana. Methods. A comprehensive eye examination was performed for 139 bankers in the Cape Coast Metropolis. Measurements of ergonomic practices at workstations were carried out and self-administered questionnaires were used to collect socio-demographic data, symptoms of CVS and associated factors as well as knowledge, attitudes and practices of the bankers on CVS. Descriptive statistics and logistic regression were carried out to compute the different proportions and relevant associations. Results. Headaches (73.4%), eyestrain (65.5%) and itching (63.3%) were the most common reported symptoms. The prevalence of CVS in the study population was 71.2% with a high level of poor ergonomic practices (78.4%) at computer workstations. With regard to knowledge, attitudes and practices of the participants on CVS, 68.3% of the participants had low levels of knowledge on CVS, while 90.6% had negative attitudes towards CVS and 46.0% of the participants had poor practices. Conclusion. Bankers had a high prevalence of CVS. Ergonomic practices, females and computer usage were all associated significantly with the presence of CVS.

Clinical relevance: Home-isolation and social distancing during the COVID-19 pandemic caused increased use of digital devices, posing a greater risk of developing digital eye strain-related symptoms. Eye-care professionals should educate patients about limiting screen time and managing digital eye strain symptoms. Background: This study aimed to evaluate the COVID-19 isolation’s impact on digital device use by comparing hours spent on digital devices before and during the 24-hour curfew in Saudi Arabia, while assessing the symptoms associated with digital eye strain. Methods: A self-reported questionnaire was used to compare the total hours per day, either continuous or intermittent, spent on digital devices during and before curfew, and the association of these durations with digital eye strain. Results: A total of 1,939 participants, (mean ± SD: 33 ± 12.2 years and 72% women) were recruited. Results showed a significant difference between usage duration before and during curfew. Digital eye strain incidence was 78% during the curfew. Chi-squared analysis indicated most symptoms are associated with usage duration and employment status. Multivariate analysis revealed significant associations between digital eye strain and the following factors: using more than one device (odds ratio 1.208, 95% confidence interval: 1.068-1.3661), age, optical correction, employment status, gender, using rewetting drops, and usage duration. Conclusions: In this population, prolonged use of digital devices significantly increased during home-isolation. Digital eye strain incidence increased during curfew. Regular eye exams should be encouraged to ensure the use of optimum prescription use and meet the specific visual demands required for the use of digital devices. Eye-health strategies and awareness campaigns should be employed on the importance of regular eye exams, decreasing screen time, practising the 20-20-20 rule, and the use of rewetting drops to help reduce the symptoms of digital eye strain during this period.

Digital display use has been accepted as a contributing factor to dry eye disease. Nowadays, plenty of new models of digital displays have been developed, and the differences in their nature and the ways in which they are set and used may contribute to differences in the eye-related problems they cause.This study aimed to analyze the differences in ocular surface, tear film, and visual fatigue parameters after reading on different digital displays, with and without initial instillation of artificial tears.Thirty-one healthy individuals ranging in age from 20 to 26 years (mean ± standard deviation, 21.26 ± 1.73 years) were included in this prospective clinical study. Subjects' ocular surface, tear film, and visual fatigue parameters were assessed after reading for 15 minutes on a laptop computer, tablet, e-reader, and smartphone with matching characteristics and a baseline measurement. Measurements were taken with and without the instillation of artificial tears before the reading tasks and included the Ocular Surface Disease Index questionnaire, the Computer Vision Syndrome Questionnaire, tear meniscus height, the Schirmer I test, noninvasive keratograph break-up time, osmolarity, bulbar redness, and pupil size.Statistically significant differences in the Ocular Surface Disease Index, Computer Vision the Syndrome Questionnaire, tear meniscus height, the Schirmer I test, noninvasive keratograph break-up time, osmolarity, and bulbar redness were obtained when comparing the displays (P.05). Best results were obtained with the smartphone and the e-reader. Conversely, the computer produced the highest disturbance on the ocular surface and tear film. Finally, the instillation of artificial tears revealed no statistical improvement of ocular surface or tear film parameters for the same device (P.05).Taking into account the clinical tests for dry eye diagnosis, the smartphone may be considered as the least disturbing display, producing lower dry eye signs and symptoms in comparison with other devices.

Digital eye strain (DES) is a growing occupational and public health problem and one of the most frequent reasons for seeking medical care. The objectives of this study are to identify the prevalence and to study some associated personal, ergonomic, and environmental factors of DES among information technology (IT) professionals at Tanta University, Egypt. An interview questionnaire was used to collect data related to socio-demographic, job, ergonomic and environmental characteristics. Computer vision syndrome questionnaire (CVS-Q) was used for the assessment of DES. It was used to measure ocular and visual symptoms related to computer use. CVS-Q includes 16 symptoms that are scored using two rating scales, one for frequency and the other for intensity. A total of 108 IT professionals were included. Prevalence of DES was 82.41%. The most common symptoms were headache (81.5%), burning of the eye (75.9%), and blurred vision (70.4%). Significant predictors of DES were female gender (OR = 2.845), age ≥ 35 years (OR = 1.112), daily computer use more than 6 h (OR = 1.351), duration of work more than 10 years (OR = 1.793), wearing corrective glasses (OR = 5.009), distance from the monitor less than 20 in. (OR = 4.389), not using antiglare screen (OR = 0.214), no brightness adjustment of screen (OR = 0.015), not taking break time during computer work (OR = 0.007), exposure to air pollution (OR = 5.667), use of the air conditioner (OR = 23.021), and exposure to windy environments (OR = 3.588). Prevalence of DES was found to be high among IT professionals. Significant predictors of DES were female gender, older age, wearing eyeglasses, long duration of computer use, unadjusted ergonomic workstation, and dry environment. DES is a problem that can be prevented by increasing knowledge and awareness about DES by providing computer users with eye health education, periodic training on a proper ergonomic computer workstation, and adjustment of the suitable comfortable workplace environment.

The digital revolution, which has been underway since the 1980's, is disrupting our daily routines with an exponential increase in the use of screens, which has not been without consequence to our visual system. Digital eye strain (DES), or computer vision syndrome (CVS), includes all the visual symptoms secondary to the use of digital devices. DES is present in at least 50% of regular users of digital media and is defined by blurred vision, difficulty focusing, ocular irritation or burning, dry eye, visual fatigue, headaches and increased sensitivity to light. Exposure time, age, female gender, and work environment are the main factors increasing its prevalence. Its pathophysiology, still poorly understood, is felt to be multifactorial and includes disturbances in the accommodative-convergence balance and changes in the ocular surface. Regarding accommodation and convergence, the studies are mostly old and their results heterogeneous. Conversely, many studies have shown an increase in the prevalence of dry eye in screen users. Although the retinal toxicity of blue light has been proven in in vitro models, the low level of evidence in the available studies does not allow it to be clearly correlated with the symptoms of DES. The objective of this review is to condense the knowledge available in the literature on the symptoms, prevalence, pathophysiology and management of DES.

Abstract Background To investigate the differences in refraction, accommodative factors, visual parameters, and subjective symptoms after using two types of virtual reality (VR) content with different depths of perception. Methods Twenty-three volunteers, who played VR games in two modes (immersive and non-immersive) for 30 min, were enrolled. Visual parameters were examined before and after using VR. Accommodative factors were measured using static and dynamic methods. Subjective symptoms were assessed using a questionnaire. Differences according to VR content were compared, and correlations between each visual parameter were analyzed. Results There were no changes in refraction or accommodative factors after use of the VR. However, there was a significant increase in the near point of accommodation (NPA), the near point of convergence (NPC), and subjective symptom scores after using the immersive mode. Correlation analysis revealed a positive correlation between baseline values of near exophoria and mean accommodative lag of the dominant eye, and also revealed a negative correlation between NPA and mean accommodative lag in the non-dominant eye. Conclusions The use of VR for 30 min increased NPA and NPC, especially after the immersive mode was used. In addition, higher exophoria and smaller NPA is associated with increased accommodative lag after using VR.

Introduction The prescription of blue-blocking (B-B) filters for the management of visual symptoms and signs associated with the use of electronic devices is routinely performed by eye care specialists. However, the utility of B-B filters is a matter of debate and discussion by the scientific community due to the lack of evidence supporting their use. Here, we aimed to determine the effects of using B-B filters on the dynamics of the accommodative response and pupil size and perceived levels of visual discomfort, while performing a 30-min reading task at a close distance in subjects who routinely use electronic devices. Methods Nineteen healthy young adults (22.0 ± 2.7 years) read two 30-min passages on a computer screen placed at 50 cm, either while using a commercially available B-B filter or without any filter on two different days. The magnitude and variability of both the accommodative response and pupil size were dynamically measured for 60 s using the WAM-5500 open field autorefractometer at 4-5, 9-10, 14-15, 19-20, 24-25, and 29-30 min into the trial. The perceived levels of visual discomfort were also obtained. Results The lag and variability of accommodation were insensitive to the blue light level (p = 0.34 and 0.62, respectively). There was a time-on-task effect for the variability of accommodation, showing greater instability over time regardless of the blue light level. The use of the B-B filter was associated with improved reading speed (p = 0.02), with an increase of 16.5 words per minute. However, it was not associated with any significant change in pupil dynamics or the perceived levels of visual discomfort (p> 0.05 in both cases). Conclusions Our data showed that the use of a B-B filter had no effect on accommodative dynamics or visual symptomatology. Based on these findings, there is no support for the prescription of B-B filters to attenuate the visual symptoms and signs associated with the use of electronic devices in healthy young adults.

Background With the frequent use of video display units, eye fatigue is becoming more common globally. An alternative nutritional strategy is needed to prevent the aggravation of eye fatigue symptoms. Objectives The objective was to evaluate the protective effect of a novel botanical combination of lutein ester, zeaxanthin, and extracts of blackcurrant, chrysanthemum, and goji berry on adults with eye fatigue in a randomized, double-blind, placebo-controlled clinical trial. Methods We randomly allocated 360 participants into 4 groups to receive placebo and 3 doses of our formula (chewable tablets, containing 6 mg, 10 mg, or 14 mg of lutein) once daily for 90 d. Each participant had 3 visits at baseline (V1), 45 d (V2), and 90 d (V3) during the study. Results Intervention with the formula improved individual scores of eye fatigue symptoms, including eye soreness, blurred vision, dry eye, foreign body sensation, and tearing. Compared with placebo, the formula at all 3 doses significantly decreased the total score of eye fatigue symptoms and increased the visuognosis persistence time at both V2 and V3. According to the Schirmer test, both 10-mg and 14-mg lutein formula groups had improved tear secretion at V3 compared with the placebo. The keratography results indicated that the first tear break-up time, average tear break-up time, and tear meniscus height were significantly increased after formula intervention. The formula at all 3 doses significantly increased the macular pigment optical density at V2 and V3 compared with the placebo, whereas optical coherence tomography showed no significant difference in retinal thickness and retinal volume across all groups at both visits. Conclusions Our botanical formula improves eye fatigue, dry eye, and macular function without changing the retinal structure, and thus it could serve as an effective nutritional strategy in improving eye fatigue without causing serious side effects.Clinical Trial Registry: chictr.org.cn (ChiCTR1800018987).

Background The exoscope has been reported as a novel neurosurgical instrumentation in clinical practice. Objective To investigate the possibility that ORBEYE (OE), a novel instrument that excludes eyepiece lenses and allows for microsurgery by observation of the 4K3D monitor, could replace microscopes. Methods We report 22 clinical cases by 5 experienced neurosurgeons and the comparative results of training 10 residents. An observation study with questionnaire survey was conducted on usability. Twelve items including image quality, eyestrain, and function of the arm were evaluated. Results The following 22 clinical procedures were conducted: surgery for intracranial hemorrhage (n = 2) and brain tumor (n = 8), laminectomy (n = 3), aneurysm clipping (n = 3), vascular anastomosis (n = 2), carotid endarterectomy (n = 2), and nerve decompression (n = 1). No complications were observed. The fluorescent study, including indocyanine-green and 5-aminolevunic acid, allowed for clear depiction on the 4K monitor. The surgeon could operate in a comfortable posture. Similar to the microscope, it was possible to change the optical and viewing axes with the OE, but the OE was switched to the microscope or endoscope in hematoma removal and pituitary surgery. Residents judged that eyestrain was strong (P = .0096). Experienced neurosurgeons acting as assistants judged that the scope arm's range of movement was narrow (P = .0204). Sixty percent of residents judged that the OE was superior to the microscope. Conclusion Although based on limited experience, it was not possible to substitute the microscope with the OE in all operations; however, the OE surpasses the microscope in terms of ergonomic features.

Purpose: To determine the prevalence of symptoms of computer vision syndrome and to identify its associated factors. The secondary objective was to assess knowledge and practices related to preventing computer vision syndrome symptoms. Methods: The data for this cross-sectional study were collected through a self-administered questionnaire distributed to 713 female undergraduates studying business and medicine in Saudi Arabia. The questionnaire included computer vision syndrome validated symptoms and factors associated with computer vision syndrome development. Results: The most common symptom due to prolonged computer use was neck or shoulder pain, reported by 82.2% of the subjects. Overall, 66.5% of the subjects suffered from headache and 51.5% from dry eyes, in mild, moderate, or severe form. Business students were 1.6 times as likely as medical students to suffer from computer vision syndrome (odds ratio = 1.65; 95% confidence interval: 1.22, 2.24). The use of electronic devices for more than 5 h (odds ratio = 1.52; 95% confidence interval: 1.07, 2.16) was also associated with experiencing computer vision syndrome symptoms. Regarding computer vision syndrome prevention, factors such as hours of use, screen distance, screen brightness, and room illumination showed statistically significant difference between the two groups (p Conclusion: The prevalence of computer vision syndrome symptoms was significantly higher among business students, who reported lower awareness and poor practice measures of computer use recommendations. Relevant awareness campaigns focusing on the appropriate use of computers are highly recommended.

PURPOSE The purpose of this study was to investigate the use of handheld digital devices and the prevalence of self-reported asthenopia among college students in China and their potential relationship. METHODS Five thousand students were randomly assessed using a self-reported asthenopia questionnaire. The students' demographic characteristics and habits regarding digital device use were recorded. Univariate analysis was performed to select potential risk factors, and multivariate logistic regression was used to estimate the odds ratios for the selected risk factors of interest. RESULTS Among the 4786 students who completed the survey, the prevalence of asthenopia was 53.3%. Multivariate analysis revealed significant relationships between asthenopia and each of the following: level of digital reliance (OR 1.350, 95%CI: 1.230-1.481), workload, time spent on computer per day, sex and time spent on handheld digital devices in bed and at desk. Aerobic exercise duration (OR 0.912, 95%CI: 0.839-0.990) was found to be strong predictor of less asthenopia complaints. CONCLUSION Asthenopia appears to be common among college students in China. Preventative measures against asthenopia include limiting the amount of time spent using digital devices in bed (

SIGNIFICANCE Growing popularity of handheld digital devices imposes significant challenges to our visual system and clinical management. This study aimed to determine the effects of lens design on parameters that may influence the refractive management of pre-presbyopic adult computer users. PURPOSE To determine the effects of wearing conventional single-vision lenses (SVL) versus progressive addition lenses (PAL) on the working distance and refractive status. METHODS Adult computer users, recruited from two age cohorts (18 to 25 years, n = 19; 30 to 40 years, n = 45), were prescribed SVLs and PALs designed for use with handheld digital devices. For each lens type, the working distance and refractive shift (post-task − pre-task) were measured immediately after lens delivery (T0) and after 1 month of lens wear (T1). Working distances were recorded with an automatic ultrasound device while the participants were playing a video game. Refractive status through the subjects' glasses was measured before (pre-task) and after playing the game (post-task). Questionnaires assessing the frequencies of 10 digital work–related visual symptoms were conducted for both lens types at T1. RESULTS Switching from SVL to PAL increased the working distance in both cohorts (mean ± SEM = 1.88 ± 0.60 cm; P = .002) and induced a small but significant positive refractive shift (+0.08 ± 0.04 D, P = .021) in the older cohort at T1. In the younger cohort, the changes in working distance due to the switching lens design were correlated with myopic error (r = +0.66, P = .002). In the older cohort, the changes in refractive shift due to switching lens design were correlated with amplitude of accommodation at both time points (r for T0 and T1 = −0.32 and −0.30, respectively; both P < .05). Progressive addition lens was rated as causing less “increased sensitivity to light” compared with SVL. CONCLUSIONS Switching from SVL to PAL increased the working distance and induced a positive refractive shift in the majority of pre-presbyopic adults.

The steady, world-wide increase in myopia prevalence in children over the past decades has raised concerns. As an early intervention for axial-length-related myopia, correcting lenses have been developed (such as Defocus Incorporated Multiple Segment (DIMS) lenses), which have been shown to be effective in slowing myopia progression. Beyond this direct effect, however, it is not known whether such lenses also affect other aspects important to the wearer, such as eye fatigue, and how such effects may differ across age, as these lenses so far are typically only tested with adolescents. In the present work, we therefore investigated perceived fatigue levels according to lens type (normal vs DIMS) and age (adolescents vs adults) in a demanding visual search task (“Finding Wally”) at two difficulty levels (easy vs difficult). Whereas age and difficulty did not result in significant differences in eye fatigue, we found a clear reduction of fatigue levels in both age groups when wearing the correcting lenses. Hence, the additional accommodation of these lens types may result in less strain in a task requiring sustained eye movements at near viewing distances.

Advanced manufacturing has resulted in significant changes on the shop-floor, influencing work demands and the working environment. The corresponding safety-related effects, including fatigue, have not been captured on an industry-wide scale. This paper presents results of a survey of U.S. manufacturing workers for the: prevalence of fatigue, its root causes and significant factors, and adopted individual fatigue coping methods. The responses from 451 manufacturing employees were analyzed using descriptive data analysis, bivariate analysis and Market Basket Analysis. 57.9% of respondents indicated that they were somewhat fatigued during the past week. They reported the ankles/feet, lower back and eyes were frequently affected body parts and a lack of sleep, work stress and shift schedule were top selected root causes for fatigue. In order to respond to fatigue when it is present, respondents reported coping by drinking caffeinated drinks, stretching/doing exercises and talking with coworkers. Frequent combinations of fatigue causes and individual coping methods were identified. These results may inform the design of fatigue monitoring and mitigation strategies and future research related to fatigue development.

Background Head-mounted displays (HMDs) and virtual reality (VR) have been frequently used in recent years, and a user’s experience and computation efficiency could be assessed by mounting eye-trackers. However, in addition to visually induced motion sickness (VIMS), eye fatigue has increasingly emerged during and after the viewing experience, highlighting the necessity of quantitatively assessment of the detrimental effects. As no measurement method for the eye fatigue caused by HMDs has been widely accepted, we detected parameters related to optometry test. We proposed a novel computational approach for estimation of eye fatigue by providing various verifiable models. Results We implemented three classifications and two regressions to investigate different feature sets, which led to present two valid assessment models for eye fatigue by employing blinking features and eye movement features with the ground truth of indicators for optometry test. Three graded results and one continuous result were provided by each model, respectively, which caused the whole result to be repeatable and comparable. Conclusion We showed differences between VIMS and eye fatigue, and we also presented a new scheme to assess eye fatigue of HMDs users by analysis of parameters of the eye tracker.

To examine the effects of prolonged visual display terminal (VDT) working hours and exercise frequency on VDT-related symptoms, we recruited 944 Chinese internet staff for the study. A self-administered questionnaire survey was used to obtain the hours of daily VDT work, exercise frequency, and the physical and mental health of the participants. The daily VDT working time of participants was 8.7 hours. Musculoskeletal pain and eye complaints were prevalent, and the participants had poor mental health status. When daily VDT operation time was more than 11 hours, VDT-related symptoms, including backache (odds ratios (OR) = 3.59), wrist pain (OR = 1.88), hip pain (OR = 2.42), dry eyes (OR = 2.22), and ocular soreness (OR = 2.16) were more likely to occur, and an increased risk of serious occupational stress (OR = 6.75) and job burnout (OR = 2.66) was found in internet workers. Compared with those who never exercised, appropriate exercise frequency (three times per week) was helpful to relieve pain in the shoulders (OR = 0.28), neck (OR = 0.45), back (OR = 0.30), lower back (OR = 0.25), and wrists (OR = 0.38), as well as to prevent vision loss (OR = 0.33) and job burnout (OR = 0.42). Therefore, avoiding excessive VDT exposure and performing moderate exercise could protect the physical and mental health of internet staff from the adverse effects of VDT.

Introduction Digital eye strain (DES; computer vision syndrome) is a common cause of symptoms when viewing digital devices. Low-powered convex lenses (adds) have been recommended for the condition and “accommodative support” designs developed on this premise. The present research reports the extent to which dry eye is present in this population and the effect of convex lenses on symptoms and visual performance. Methods The CVS-Q instrument was used to select pre-presbyopic adults with the symptoms of DES. Participants received a full eye examination including an assessment of dry eye with a modified SANDE questionnaire and using DEWS I criteria. The immediate effect of low-powered convex lenses (low adds: +0.50D, +0.75D, +1.25D) was investigated using subjective preference and a double-masked comparison with plano lenses with the Wilkins Rate of Reading Test (WRRT). Throughout this testing, participants wore their full distance refractive correction, based on non-cycloplegic retinoscopy and subjective refraction. Results The signs and symptoms of dry eye were frequently present. Most participants reported a subjective preference for low adds, with +0.75D the most commonly preferred lens. Low adds (+0.50D and +0.75D; but not +1.25D) were associated with significantly improved performance at the WRRT. One quarter of participants read more than 10% faster with these additional convex lenses. Conclusions The study population was aged 20–40y and mostly worked on desktop computers. It is possible that +1.25D add may be more advantageous for people who are older or work more at closer viewing distances. Many symptomatic users of digital devices report a preference for low adds and use of these lenses is often associated with an improvement in reading performance.

To determine the efficacy of Smartphone-based exercises in conjunction with modified glasses prescription in the treatment of convergence insufficiency and fusion weakness.A total of 150 patients using glasses and having asthenopia between 15 and 30 years of age were subjected to thorough eye examination including binocular vision testing and refraction. Of them 26 individuals were found to have convergence insufficiency with fusion weakness and exophoria6 pd. Subjects with amblyopia, manifest strabismus and other ocular diseases were excluded from the study. Modified glasses (overcorrection of myopia by -0.5 D Sphunder correction of hypermetropia by +0.5 D Sph) were given along with newly designed Smartphone-based fusion exercises.Near point of convergence improved by 2.89 ± 1.08 cm, positive fusion vergence by -10.2 ± 3.25 pd and near phoria by 3.13 ± 0.32 pd (p 0.001).The current study demonstrates the efficacy of Smartphone-based fusion exercises, in conjunction with modified glasses prescriptions, in the management of symptomatic convergence and fusion insufficiency. Indeed, this novel, newly designed approach for convergence insufficiency improves symptoms by reducing near point of convergence and degree of exophoria and increasing fusional vergence.

Workers in the dry-cleaning industry are exposed to organic solvents that may cause eye irritation and tear film changes. Objective To quantify changes in the ocular surface and tear film in dry cleaners exposed to organic solvents and associate these changes with ocular irritation as reported in a symptom questionnaire for dry eye diagnosis. Methods This was a case and control study in which the characteristics and eye-irritation symptoms were compared between two groups of 62 participants that were either exposed or not exposed to organic solvents. A general optometric examination and the following test were performed: lipid interferometry, Lissamine Green Stain, tear breakup time, Schirmer I, conjunctival impression cytology and the Donate dry eye symptoms questionnaire. Results Sixty-five percent of exposed workers obtained a higher score than 13 on the Donate dry eye symptoms questionnaire which indicated the presence of more irritation symptoms than those in the non- exposed group. A Chi-square analysis indicated the exposed group reported significantly higher incidences (P

Recent studies on brain-computer interfaces (BCIs) based on the steady-state visual evoked potential (SSVEP) have demonstrated their use to control objects or generate commands in virtual reality (VR) environments. However, most SSVEP-based BCI studies performed in VR environments have adopted visual stimuli that are typically used in conventional LCD environments without considering the differences in the rendering devices (head-mounted displays (HMDs) used in the VR environments). The proximity between the visual stimuli and the eyes in HMDs can readily cause eyestrain, degrading the overall performance of SSVEP-based BCIs. Therefore, in the present study, we have tested two different types of visual stimuli—pattern-reversal checkerboard stimulus (PRCS) and grow/shrink stimulus (GSS)—on young healthy participants wearing HMDs. Preliminary experiments were conducted to investigate the visual comfort of each participant during the presentation of the visual stimuli. In subsequent online avatar control experiments, we observed considerable differences in the classification accuracy of individual participants based on the type of visual stimuli used to elicit SSVEP. Interestingly, there was a close relationship between the subjective visual comfort score and the online performance of the SSVEP-based BCI: most participants showed better classification accuracy under visual stimulus they were more comfortable with. Our experimental results suggest the importance of an appropriate visual stimulus to enhance the overall performance of the SSVEP-based BCIs in VR environments. In addition, it is expected that the appropriate visual stimulus for a certain user might be readily selected by surveying the user’s visual comfort for different visual stimuli, without the need for the actual BCI experiments.

Vergence prism adaptability was evaluated in subjects with high symptomatic and asymptomatic heterophoria and compared to individuals with a heterophoria within normal range (the control group). A computer haploscope was used to measure phoria values and changes in the eye position after introducing 6 prism diopters base out in front of the right eye. Phoria values were measured with a nonius paradigm every minute for a period of 10 minutes during adaptation. The results showed that subjects with symptomatic heterophoria are characterized by a lower rate of prism adaptation and adapted to a smaller extent with respect to the control group. The group with high but asymptomatic heterophoria showed prolonged adaptation time but after several minutes of binocular viewing the subjects were able to adapt to the prism to a level similar to the control group. These findings suggest that an impairment in the slow vergence control system may be responsible for the inability to fully reduce vergence effort, which results in poor vergence ranges and asthenopic symptoms during prolonged viewing.

Exposure to additional environmental stress during computer work, such as visual and psychological demands, is associated with increased eye and neck discomfort, altered moods, and reduced well-being. The aim of this study is to elucidate further how subjective responses in healthy, young females with normal binocular vision are affected by glare and psychological stress during computer work, and to investigate possible associations between trapezius muscle blood flow and neck pain development. 43 females participated in a laboratory experiment with a within-subject design. Four 10-min computer work conditions with exposure to different stressors were performed at an ergonomically optimal workstation, under the following series of conditions: no additional stress, visual stress (induced as direct glare from a large glare source), psychological stress, and combined visual and psychological stress. Before and immediately after each computer work condition, questionnaires regarding different visual and eye symptoms, neck and shoulder symptoms, positive and negative state moods, perceived task difficulty, and perceived ambient lighting were completed. Associations between neck pain and trapezius muscle blood flow were also investigated. Exposure to direct glare induced greater development of visual/eye symptoms and discomfort, while psychological stress exposure made participants feel more negative and stressed. The perception of work lighting during glare exposure was closely related to perceived stress, and associations between visual discomfort and eyestrain, and neck pain were observed in all conditions. Furthermore, participants with high trapezius muscle blood flow overall reported more neck pain, independent of exposure. Exposure to visual and psychological stresses during computer work affects the development of symptoms and negative moods in healthy, young females with normal binocular vision, but in different ways. The results also demonstrate the complex interactions involved in symptom development and lighting appraisal during computer work. When optimizing computer workstations, the complexity of the field must be taken into account, and several factors, including visual conditions, must be considered carefully.

The use of virtual reality (VR) is associated with several adverse effects including dizziness, headache, and motion sickness. This study investigates how full-immersion VR games cause changes in static balance with associated adverse effects, and whether a fixed or a changing game background is more likely to contribute to such problems. Static balance and adverse effects (eye fatigue and dizziness) were measured in 15 healthy adults under three conditions: baseline; after a full-immersion virtual reality game (PlayStation 4 Pro and PlayStation® VR headset) with a fixed background (15 min); and after a full-immersion virtual reality game with a unfixed background (15 min). Static balance was measured with an AMTI force plate, while eye fatigue and dizziness were measured with the Virtual Reality Symptom Questionnaire (VRSQ) and the Simulator Sickness Questionnaire (SSQ). It was determined that playing a full-immersion VR game had a negative effect on static balance and produced several adverse effects including eye fatigue and dizziness. Moreover, sway velocity and sway length increased significantly in the game with a moving background compared to both the baseline and the game with a fixed background (p < 0.05); VRSQ and SSQ were also significantly higher in this case. It is thus preferable from the perspective of reducing adverse effects that only fixed-background full-immersion VR games be used in rehabilitative interventions.

In augmented reality (AR) environments, information is often distributed between real world and virtual contexts, and often appears at different distances from the user. Therefore, to integrate the information, users must repeatedly switch context and refocus the eyes. To focus at different distances, the user's eyes must accommodate, which when done repeatedly can cause eyestrain and degrade task performance. An experiment was conducted that examined switching context and focal distance between a real and an AR environment, using a text-based visual search task and a monocular optical see-through AR display. Both context switching and focal distance switching resulted in significantly reduced performance. In addition, repeatedly performing the task caused visual fatigue to steadily increase. Performance was particularly poor for virtual text presented at optical infinity, and for target letters that participants tried to read before their eyes had completely accommodated to a new focal distance. The results show that context switching and focal distance switching are important AR user interface design issues.

Background: Visual display terminals (VDTs) emitting blue light can cause ocular disorders including eye fatigue. Some dietary constituents have been reported to be effective in improving ocular disorders while few clinical studies have been performed. We evaluated the effects of heat-killed Lactobacillus paracasei KW 3110 on improving ocular disorders and symptoms of eye fatigue among healthy human subjects with VDT loads. Methods: In vitro, the effect of L. paracasei KW3110 on blue light-induced human retinal pigment epithelial (ARPE-19) cell damage. For clinical studies, 62 healthy Japanese volunteers of 35 to 45 years of age who had experienced eye fatigue were randomized into two groups and given a placebo or L. paracasei KW3110-containing supplements for eight weeks. The primary endpoint was changes in VDT load-induced eye fatigue as determined by critical flicker frequency four and eight weeks after the start of supplementation. Results: In vitro, blue light-induced human retinal cell death was suppressed with the culture supernatants of cells treated with L. paracasei KW3110. In clinical study, the VDT load-induced reduction of critical flicker frequency tended to be milder in the L. paracasei KW3110 group when compared with the placebo group during the fourth week. Subgroup analysis classified by the degree of eye fatigue showed that the VDT load-induced reduction of critical flicker frequency was significantly better in the high-level eye fatigue subjects from the L. paracasei KW3110 group when compared with the placebo group during the fourth week (p = 0.020). Conclusions: L. paracasei KW3110 suppressed blue light-induced retinal pigment epithelial cell death. In the clinical study, ingestion of L. paracasei KW3110 had a potential to improve eye fatigue induced by VDT loads especially high levels of eye fatigue. However, further studies should be required to show more dependable clinical efficacy of L. paracasei KW3110.

This study examined the effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction. Five 27″ rear-screen mock-ups with distinct curvature radii (600R, 1140R, 2000R, 4000R, and flat) were used. Ten individuals per display curvature completed a series of four 15 min comparison-proofreading trials at a 600 mm viewing distance. Only proofreading speed benefited from display curvature, with 600R providing the highest mean proofreading speed. Proofreading speed increased and accuracy decreased for all display curvatures over the 1 h proofreading period. Visual discomfort, visual fatigue, and mental workload increased during the first 15 min of proofreading. A decrease in critical fusion frequency during that period indicated increases in visual fatigue and mental workload. A short break between 15 min proofreading tasks could be considered to prevent further degradation of task performance and ocular health.

BACKGROUND AND OBJECTIVE: To examine the human visual performance (wavefront aberration) and subjective questionnaire (SQ) of visual fatigue when viewing 2-D and 3-D movies. METHODS: Thirty healthy adults observed 2-D and 3-D movies on the same television from a 3m distances during 2D, 3D-A (with better 3D glasses), and 3D-B (with poorer 3D glasses) viewing conditions. Visual quality index, including modulation transfer function index (MTFI), higher order aberration root mean square (RMS), vertical coma (VC), horizontal coma (HC) and spherical aberration (SA), were assessed before and after each viewing condition. One-way repeated measures ANOVA was performed to assess the changes of each test variable before and after movie viewing. RESULTS: Participants watching movies with 3D-B conditions experienced higher change of MTFI, RMS, VC and HC but smaller SQ, compared with 2D and 3D-A (P< 0.05). Additionally, higher MTFI but smaller SQ was found for 3D-A compared with 2D viewing condition (P< 0.05). CONCLUSIONS: While prolonged viewing 2-D and 3-D movies would lead to poorer visual performance, 3-D glasses with better quality can play the major role in reducing visual ability for users. The change of human eye wavefront aberration might be useful for the evaluation of visual fatigue in the future.

The green tea (Camellia sinensis L.) cultivar “Sunrouge” contains anthocyanins, catechins and flavonols. To determine whether ingesting green tea containing anthocyanins improves visual function and blood pressure (BP) in healthy adults, a randomized, double-blind, placebo-controlled study was performed. A total of 120 healthy subjects, aged between 20 and 60 years and with a systolic BP (SBP) value of ≤125 and

To study the accommodative dynamics for predictable and unpredictable stimuli using manual and automated accommodative facility tests Materials and Methods: Seventeen young healthy subjects were tested monocularly in two consecutive sessions, using five different conditions. Two conditions replicated the conventional monocular accommodative facility tests for far and near distances, performed with manually held flippers. The other three conditions were automated and conducted using an electro-optical system and open-field autorefractor. Two of the three automated conditions replicated the predictable manual accommodative facility tests. The last automated condition was a hybrid approach using a novel method whereby far and near-accommodative-facility tests were randomly integrated into a single test of four unpredictable accommodative demands.The within-subject standard deviations for far- and near-distance-accommodative reversals were (±1,±1) cycles per minute (cpm) for the manual flipper accommodative facility conditions and (±3, ±4) cpm for the automated conditions. The 95% limits of agreement between the manual and the automated conditions for far and near distances were poor: (-18, 12) and (-15, 3). During the hybrid unpredictable condition, the response time and accommodative response parameters were significantly (p 0.05) larger for accommodation than disaccommodation responses for high accommodative demands only. The response times during the transitions 0.17/2.17 D and 0.50/4.50 D appeared to be indistinguishable between the hybrid unpredictable and the conventional predictable automated tests.The automated accommodative facility test does not agree with the manual flipper test results. Operator delays in flipping the lens may account for these differences. This novel test, using unpredictable stimuli, provides a more comprehensive examination of accommodative dynamics than conventional manual accommodative facility tests. Unexpectedly, the unpredictability of the stimulus did not to affect accommodation dynamics. Further studies are needed to evaluate the sensitivity of this novel hybrid technique on individuals with accommodative anomalies.